Brazing is a metal-joining process whereby a filler metal is heated above its melting point and distributed between two or more close-fitting parts by capillary action. In particular, the filler metal is brought slightly above its melting (liquidus) temperature while protected by a suitable atmosphere, usually a flux. It then flows over the base metal (known as wetting) and is then cooled to join the workpieces together by creating a metallurgical bond between them at the atomic level. It is similar to soldering, except the temperatures used to melt the filler metal are above 450° C. (842° F.), or, as traditionally defined in the United States, above 800° F. (427° C.).
Existing brazing fixtures support the components to be brazed, and are made using conventional methods. In particular, frames and workpiece supports/positioning members are machined, formed, and/or welded together such that a component may be placed into the fixture, brazed, and removed from the fixture. In addition, although parts may be oriented correctly when first placed in the fixture that is to support them during brazing, differences in thermal expansion rates between the parts and the fixture surface tend to distort and shift the parts with respect to each other, which can be unacceptable with precision parts. Accordingly, in order to perform at, and even withstand, the elevated temperatures required, Xu et al., in U.S. Pat. No. 6,129,257 describe a high temperature brazing fixture made of the same high temperature alloy as the workpiece to be brazed, such that the fixture exhibits the same coefficient of thermal expansion as the workpiece. Over time and repeated brazing operations, the fixture may come out of alignment and/or need to be reworked or replaced.
The present disclosure is directed toward overcoming one or more of the problems discussed above as well as additional problems discovered by the inventor.